Ressincronização ventricular: comparando os marcapassos biventriculares com os marcapassos bifocais de ventrículo direito

Abstract

SummaryObjective: To analyze the conventional biventricular pacing (BV) and the bifocal (BF) right ventricular (RV) pacing, and to perform a comparative analysis of these two techniques in relation to clinical, functional and echocardiographic parameters in a population without the exclusion criteria of the major studies.Methods: A prospective non-randomized analysis of 36 patients undergoing surgery for multisite pacemaker implantation due to QRS ≥ 130 ms, severe left ventricular dysfunction, and NYHA functional class III or ambulatory class IV congestive heart failure was performed.Results: Favorable results of resynchronization were obtained with both techniques, with no significant differences in the comparison of the two groups, except for a higher QRS narrowing in the BV group, and a trend of a lower number or hospital admissions in the BV group. When the groups were analyzed separately and compared before and after the procedures, we observed that improvement was much more significant in the biventricular group, as were the more statistically relevant rates.Conclusion: Cardiac resynchronization therapy proved to be an efficient therapy in both groups analyzed, although with more significant outcomes in the biventricular group. (Arq Bras Cardiol 2007;88(6):596-603)

Síndromes neuralmente mediadas

“…The lowest incidence of the latter, contrary to what is described in the literature 3,7 , was a consequence of possible pre-selection of patients because the study was conducted with patients that had sought a cardiology hospital. As expected, this group presented higher mortality rate than the groups of patients with vasovagal syncope or with dysautonomia 36,37 .…”

“…High mortality rate was also observed in patients with syncope of established cardiac etiologies, as the congenital long QT syndrome 33 and the primary polimorphic ventricular tachycardia 37 .…”

Bifocal Right Ventricular Resynchronization for the Failing Right Ventricle

“…Bifocal RV pacing has been tested in small studies as a treatment option for patients with LV systolic dysfunction and heart failure 2–4 . These studies have shown clinical and echocardiographic improvement 2–4 although in a lesser extent as compared with biventricular pacing 3 . The capacity of shortening the LV activation time with bifocal RV pacing is probably the underlying mechanism to benefit from this pacing mode 5,6 .…”